i2c: rcar: add FastMode+ support for Gen4

To support FM+, we mainly need to turn the SMD constant into a parameter
and set it accordingly. That also means we can finally fix SMD to our
needs instead of bailing out. A sanity check for SMD then becomes a
sanity check for 'x == 0'. After all that, activating the enable bit for
FM+ is all we need to do. Tested with a Renesas Falcon board using R-Car
V3U.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: introduce Gen4 devices

So far, we treated Gen4 as Gen3. But we are soon adding FM+ as a Gen4
specific feature, so prepare the code for the new devtype.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: fix error code in probe()

Return an error code if devm_reset_control_get_exclusive() fails.
The current code returns success.

Fixes: 0e864b552b23 ("i2c: rcar: reset controller is mandatory for Gen3+")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: improve accuracy for R-Car Gen3+

With some new registers, SCL can be calculated to be closer to the
desired rate. Apply the new formula for R-Car Gen3 device types.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: reset controller is mandatory for Gen3+

Initially, we only needed a reset controller to make sure RXDMA works at
least once per transfer. Meanwhile, documentation has been updated. It
now says that a reset has to be performed prior every transaction, even
if it is non-DMA. So, make the reset controller a requirement instead of
being optional. And bail out if resetting fails.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: remove open coded DIV_ROUND_CLOSEST

It improves readability if we use the available helper.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: calculate divider instead of brute-forcing it

Instead of trying all values, we can actually compute it as the comment
suggests. It is unclear what the comment means with "involved", it works
nicely.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: properly format a debug output

Use proper types and spacing.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: avoid non-standard use of goto

Kernel functions goto somewhere on error conditions. Using goto for the
default path is irritating. Let's bail out on error instead and use a
proper retval.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

I2C: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: Remove #ifdef guards for PM related functions

Use the new PM macros for the suspend and resume functions to be
automatically dropped by the compiler when CONFIG_PM or
CONFIG_PM_SLEEP are disabled, without having to use #ifdef guards.

This has the advantage of always compiling these functions in,
independently of any Kconfig option. Thanks to that, bugs and other
regressions are subsequently easier to catch.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230722115310.27681-2-paul@crapouillou.net
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

i2c: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Chris Pringle <chris.pringle@phabrix.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Tali Perry <tali.perry@nuvoton.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: move drivers from strlcpy to strscpy

Follow the advice of the below link and prefer 'strscpy'. Conversion is
easy because no driver used the return value and has been done with a
simple sed invocation.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: use flags instead of atomic_xfer

i2c-rcar already has priv->flags. This patch adds a new persistent flag
ID_P_NOT_ATOMIC and uses it to save the extra variable. The negation of
the logic was done to make the code more readable.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
[wsa: negated the logic, rebased, updated the commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: REP_AFTER_RD is not a persistent flag

Previous refactoring makes it easy now to convert the above flag to a
non-persistent one. This is more appropriate and easier to maintain.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: use BIT macro consistently

Easier to read and ensures proper types.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: refactor handling of first message

After moving ICMSR handling to interrupt handlers previously to fix a
race condition, we can now also move ICMSR handling for the first
message out of the function to prepare a message. By introducing a
seperate function to initialize the first message, we can not only
remove some code duplication but the remaining code is also easier to
follow. The function to prepare a message is much simpler without ICMSR
handling.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: avoid race condition with SMIs

A customer experienced a race condition with 'repeated starts' when a
System Management Interrupt took over for 30us and more. The problem was
that during the SMI a new MAT interrupt came in because we set up the
'repeated start' condition. But the old one was not acknowledged yet.
So, when it was acknowledged after the SMI, the new MAT interrupt was
lost, confusing the state machine of the driver.

The fix consists of two parts. First, we do not clear the status
register for 'repeated starts' when preparing the next message anymore.
The interrupt handlers for sending and receiving data is now solely
responsible for that and it makes the code easier to follow, in fact.
Secondly, clearing the status register is now split up to handle MAT
interrupts independently. This avoids the race condition because the old
MAT interrupt will be now cleared before we initiate the "repeated
start" condition.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: fix PM ref counts in probe error paths

We have to take care of ID_P_PM_BLOCKED when bailing out during probe.

Fixes: 7ee24eb508d6 ("i2c: rcar: disable PM in multi-master mode")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: add support for I2C_M_RECV_LEN

With this feature added, SMBus Block reads and Proc calls are now
supported. This patch is the best of two independent developments by
Wolfram and Bhuvanesh + Andrew, refactored again by Wolfram.

Signed-off-by: Bhuvanesh Surachari <bhuvanesh_surachari@mentor.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: Add R-Car Gen4 support

Add support for the I2C Bus Interface on R-Car Gen4 SoCs (e.g. R-Car
S4-8) by matching on a family-specific compatible value.

While I2C on R-Car Gen4 does support some extra features (Slave Clock
Stretch Select), for now it is treated the same as I2C on R-Car Gen3.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: removed incorrect "FM+" from commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: update to new DMAENGINE API when terminating

dmaengine_terminate_all() is deprecated. When converting the existing
calls, it turned out that the termination in the interrupt handlers was
superfluous and only a side effect of simply calling
rcar_i2c_cleanup_dma(). As either no DMA transfers have been submitted
yet or the last one has successfully completed, there is nothing to
terminate and we can leave it out. So, merge the DMA unmap and cleanup
function to save some code. Then, add a flag if the new cleanup function
needs to terminate DMA. This is only the case for the erorr handling in
the main thread, so we can finally switch from dmaengine_terminate_all()
to dmaengine_terminate_sync() here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: enable interrupts before starting transfer

We want to enable the interrupts _before_ starting the transfer because
it is good programming style and also the proposed order in the R-Car
manual. There is no difference in practice because it doesn't matter in
which order both conditions appear if we wait for both to happen.

Signed-off-by: Ryo Kataoka <ryo.kataoka.wt@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: Drop "renesas,i2c-rcar"

The compatible value "renesas,i2c-rcar" was deprecated in commit
ad4a8dc3fec6485b ("i2c: rcar: Add per-Generation fallback bindings"),
and never had any users in upstream Linux. Drop its match entry from
the driver.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: add IRQ check

The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to devm_request_irq() (which
takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding
an original error code. Stop calling devm_request_irq() with the
invalid IRQ #s.

Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: implement atomic transfers

Implements atomic transfers. Tested by rebooting an r8a7790 Lager board
after connecting the i2c-rcar controller to the PMIC in
arch/arm/boot/dts/r8a7790-lager.dts like so:

compatible = "i2c-demux-pinctrl";
pinctrl-names = "default";
pinctrl-0 = <&pmic_irq_pins>;
- i2c-parent = <&iic3>, <&i2c3>;
+ i2c-parent = <&i2c3>, <&iic3>;
i2c-bus-name = "i2c-pwr";
#address-cells = <1>;
#size-cells = <0>;

Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: protect against supurious interrupts on V3U

V3U creates spurious interrupts which we need to handle. This costs time
until BUS_PHASE_DATA can be activated which is problematic for Gen2 SoCs
and earlier. Because of this we introduce two interrupt handlers here
which will call a generic main irq function once the timing critical
stuff is done.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: make sure irq is not threaded on Gen2 and earlier

Ensure this irq runs as fast as possible.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: optimize cacheline to minimize HW race condition

'flags' and 'io' are needed first, so they should be at the beginning of
the private struct.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: faster irq code to minimize HW race condition

To avoid the HW race condition on R-Car Gen2 and earlier, we need to
write to ICMCR as soon as possible in the interrupt handler. We can
improve this by writing a static value instead of masking out bits.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: add HostNotify support

The I2C core can now utilize a slave interface to handle SMBus
HostNotify events. Enable it in this driver.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: refactor and shorten timeout when resetting

LOOP_TIMEOUT was only used back then because we didn't want to introduce
another constant. The timeout value can easily be a magnitude shorter
because the typical range is 3us - 8us. Refactor the code to use the
poll_timeout helper, use a specific timeout value and get rid of the
ugly LOOP_TIMEOUT constant.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: improve bus busy detection

I2C doesn't define a timeout for bus busy, so an arbitrary value like
LOOP_TIMEOUT is not a good idea. Let's use the timeout value in struct
adapter which is meant for such cases and is user-configurable (via
IOCTL). To reduce the load, wait 10us instead of 1us which is good
enough for the slow frequencies used by I2C. Finally, use the
poll_timeout helper instead of open coding it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: in slave mode, clear NACK earlier

Currently, a NACK in slave mode is set/cleared when SCL is held low by
the IP core right before the bit is about to be pushed out. This is too
late for clearing and then a NACK from the previous byte is still used
for the current one. Now, let's clear the NACK right after we detected
the STOP condition following the NACK.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: avoid race when unregistering slave

Due to the lockless design of the driver, it is theoretically possible
to access a NULL pointer, if a slave interrupt was running while we were
unregistering the slave. To make this rock solid, disable the interrupt
for a short time while we are clearing the interrupt_enable register.
This patch is purely based on code inspection. The OOPS is super-hard to
trigger because clearing SAR (the address) makes interrupts even more
unlikely to happen as well. While here, reinit SCR to SDBS because this
bit should always be set according to documentation. There is no effect,
though, because the interface is disabled.

Fixes: 7b814d852af6 ("i2c: rcar: avoid race when unregistering slave client")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: slave: only send STOP event when we have been addressed

When the SSR interrupt is activated, it will detect every STOP condition
on the bus, not only the ones after we have been addressed. So, enable
this interrupt only after we have been addressed, and disable it
otherwise.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: rcar: always clear ICSAR to avoid side effects

On R-Car Gen2, we get a timeout when reading from the address set in
ICSAR, even though the slave interface is disabled. Clearing it fixes
this situation. Note that Gen3 is not affected.

To reproduce: bind and undbind an I2C slave on some bus, run
'i2cdetect' on that bus.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: busses: convert to devm_platform_get_and_ioremap_resource

use devm_platform_get_and_ioremap_resource() to simplify code, which
contains platform_get_resource() and devm_ioremap_resource(), it also
get the resource for use by the following code.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: clean up after refactoring i2c_timings

The pointer is not really needed anymore since we have the timings
struct available in the function itself now. Remove the pointer and
access the struct directly.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: Consolidate timings calls in rcar_i2c_clock_calculate()

Move i2c_parse_fw_timings() to rcar_i2c_clock_calculate() to consolidate
timings calls in one place.

While here, replace hard coded values with standard bus frequency definitions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: core: Allow override timing properties with 0

Some drivers may allow to override properties with 0 value when defaults
are not in use, thus, replace memset() with corresponding per property
update.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: Remove superfluous call to clk_get_rate()

Variable "rate" already contains the current clock rate, so use that
rather than calling clk_get_rate() again.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: avoid race when unregistering slave client

After we disabled interrupts, there might still be an active one
running. Sync before clearing the pointer to the slave device.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Reported-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: wait for data empty before starting DMA

When sending with DMA, the driver transfers the first byte with PIO (as
documented). However, it started DMA right after the first byte was
written. This worked, but was not according to the datasheet which
suggests to wait until data register was empty again. Implement this.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: let DMA enable routine return success status

We will need to know if enabling DMA was successful in a later patch.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: sanity check for minimal DMA length

Use a macro for the hardcoded value and apply a build check. If it is
not met, the driver logic will not work anymore.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: explain the lockless design

To make sure people can understand the lockless design of this driver
without the need to dive into git history, add a comment giving an
overview of the situation.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix concurrency issue related to ICDMAER

This patch fixes the problem that an interrupt may set up a new I2C
message and the DMA callback overwrites this setup.

By disabling the DMA Enable Register(ICDMAER), rcar_i2c_dma_unmap()
enables interrupts for register settings (such as Master Control
Register(ICMCR)) and advances the I2C transfer sequence.

If an interrupt occurs immediately after ICDMAER is disabled, the
callback handler later continues and overwrites the previous settings
from the interrupt. So, disable ICDMAER at the end of the callback to
ensure other interrupts are masked until then.

Note that this driver needs to work lock-free because there are IP cores
with a HW race condition which prevent us from using a spinlock in the
interrupt handler.

Reproduction test:
1. Add a delay after disabling ICDMAER. (It is expected to generate an
interrupt of rcar_i2c_irq())

void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv)
{
...
rcar_i2c_write(priv, ICDMAER, 0);
usleep_range(500, 800)
...
priv->dma_direction = DMA_NONE;
}

2. Execute DMA transfers

$ i2ctransfer -y 4 w9@0x6a 1 1+ r16

3. A log message of BUG_ON() will be displayed.

Fixes: 73e8b0528346 ("i2c: rcar: add DMA support")
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: updated test case to be more reliable, added note to comment]
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor TCYC handling

The latest documentation made it clear that we need to initialize the
TCYC value independently of DMA. The old code used TCYC06 (wrongly) for
non-DMA transfers. The new code sets TCYC up independently from DMA.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: comment maintenance

Update copyright years and remove a comment which grew incorrect and
useless over time.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: Fix clients using i2c from suspend callback

When doing s2idle/s2ram on Salvator-X(S):

WARNING: CPU: 2 PID: 971 at drivers/i2c/i2c-core-base.c:1869 __i2c_transfer+0x608/0x910
[...]
Call trace:
__i2c_transfer+0x608/0x910
i2c_smbus_xfer_emulated+0x158/0x5b0
__i2c_smbus_xfer+0x17c/0x818
i2c_smbus_xfer+0x64/0x98
i2c_smbus_read_byte_data+0x40/0x70
cs2000_bset.isra.1+0x2c/0x68
__cs2000_set_rate.constprop.7+0x80/0x148
cs2000_resume+0x18/0x20
dpm_run_callback+0x74/0x330
device_resume_early+0xd4/0x120
dpm_resume_early+0x158/0x4f8
suspend_devices_and_enter+0x36c/0xd98
[...]

On second resume, the sound driver fails with:

cs2000-cp 2-004f: pll lock failed
rcar_sound ec500000.sound: can't use clk 1

As the CS2000 clock driver needs to send I2C messages during suspend,
the I2C controller driver should be suspended later, and resumed
earlier. Fix this by using the noirq sleep ops instead of the normal
sleep ops, which are called after the late sleep ops, as used by the
CS2000 clock driver.

Fixes: 18569fa89a4db9ed ("i2c: rcar: add suspend/resume support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add suspend/resume support

Because the adapter will be set up before every transaction anyhow, we
just need to mark it as suspended to the I2C core.

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: check bus state before reinitializing

We should check the bus state before reinitializing the IP core.
Otherwise, the internal bus busy state which also tracks multi-master
activity is lost.

Credits go to the Renesas BSP team for suggesting this change.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: ae481cc13965 ("i2c: rcar: fix resume by always initializing registers before transfer")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: cleanup DMA for all kinds of failure

DMA needs to be cleaned up not only on timeout, but on all errors where
it has been setup before.

Fixes: 73e8b0528346 ("i2c: rcar: add DMA support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: use SPDX identifier for Renesas drivers

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: implement STOP and REP_START according to docs

When doing a REP_START after a read message, the driver used to trigger
a STOP first which would then be overwritten by REP_START. This was the
only stable method found when doing the last refactoring. However, this
was not in accordance with the documentation.

After research from our BSP team and myself, we now can implement a
version which works and is according to the documentation. The new
approach ensures the ICMCR register is only changed when really needed.

Tested on a R-Car Gen2 (H2) and Gen3 with DMA (M3N).

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor private flags

Use BIT macro to avoid shift-31-problem, indent a little more and use
GENMASK to make it easier to add new flags.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use core to detect 'no zero length' quirk

And don't reimplement in the driver.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: handle RXDMA HW behaviour on Gen3

On Gen3, we can only do RXDMA once per transfer reliably. For that, we
must reset the device, then we can have RXDMA once. This patch
implements this. When there is no reset controller or the reset fails,
RXDMA will be blocked completely. Otherwise, it will be disabled after
the first RXDMA transfer. Based on a commit from the BSP by Hiromitsu
Yamasaki, yet completely refactored to handle multiple read messages
within one transfer.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: rcar: handle RXDMA HW behaviour on Gen3

On Gen3, we can only do RXDMA once per transfer reliably. For that, we
must reset the device, then we can have RXDMA once. This patch
implements this. When there is no reset controller or the reset fails,
RXDMA will be blocked completely. Otherwise, it will be disabled after
the first RXDMA transfer. Based on a commit from the BSP by Hiromitsu
Yamasaki, yet completely refactored to handle multiple read messages
within one transfer.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use the new get_bus_free callback

To break out of recovery as early as possible, feed back the bus_free
logic state.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: make use of i2c_8bit_addr_from_msg

Because it looks neater.

For diolan, this allows factoring out some code that is now common
between if and else.

For eg20t, pch_i2c_writebytes is always called with a write in
msgs->flags, and pch_i2c_readbytes with a read.

For imx, i2c_imx_dma_write and i2c_imx_write are always called with a
write in msgs->flags, and i2c_imx_read with a read.

For qup, qup_i2c_write_tx_fifo_v1 is always called with a write in
qup->msg->flags.

For stu300, also restructure debug output for resends, since that
code as a result is only handling debug output.

Reviewed-by: Guenter Roeck <linux@roeck-us.net> [diolan]
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [efm32 and imx]
Acked-by: Linus Walleij <linus.walleij@linaro.org> [stu300]
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: enhance comment to avoid regressions

Give a clear testcase for people wishing to change this code. It is also
a reminder for me if people ask about it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix mask value of prohibited bit

According to documentation, Bit 7 of ICMSR is unused and 0 should be
written to it. Fix the mask accordingly.

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
[wsa: edited commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix some trivial typos in comments

Nothing big, but they get annoying after a while ;)

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: implement bus recovery

We can force levels of SCL and SDA, so we can use that for bus recovery.
Note that we cannot read SDA back, because we will only get the internal
state of the bus free detection.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: skip DMA if buffer is not safe

This HW is prone to races, so it needs to setup new messages in irq
context. That means we can't alloc bounce buffers if a message buffer is
not DMA safe. So, in that case, simply fall back to PIO.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: avoid unused ret variable

Fix smatch warning:
drivers/i2c/busses/i2c-rcar.c:628 \
rcar_i2c_request_dma_chan() warn: unused return: ret = PTR_ERR()

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: document HW incapabilities

Add recent findings (IGNORE_NAK) and document in a bit more detail why
the feature is not possible.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: use proper name for the R-Car SoC

It is 'R-Car', not 'RCar'. No code or binding changes, only descriptive text.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use correct length when unmapping DMA

Because we need to transfer some bytes with PIO, the msg length is not
the length of the DMA buffer. Use the correct value which we used when
doing the mapping.

Fixes: 73e8b0528346e8 ("i2c: rcar: add DMA support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: clarify PM handling with more comments

PM handling is correct but might be a bit subtle. Add some comments for
clarification.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix resume by always initializing registers before transfer

Resume failed because of uninitialized registers. Instead of adding a
resume callback, we simply initialize registers before every transfer.
This lightweight change is more robust and will keep us safe if we ever
need support for power domains or dynamic frequency changes.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: Add per-Generation fallback bindings

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 2 and Gen 3. But beyond that it's not clear what the
relationship between IP blocks might be. For example, I believe that
r8a7790 is older than r8a7791 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme is being adopted for
drivers for Renesas SoCs.

Also:
* Deprecate renesas,i2c-rcar. It seems poorly named as it is only
compatible with R-Car Gen 1. It also appears unused in mainline.
* Add some text to describe per-SoC bindings

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add support for r8a7796 (R-Car M3-W)

Same as r8a7795.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use proper device with dma_mapping_error

We must use the same device we used for mapping.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: don't print error when adding adapter fails

The core will do this for us now.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use dma_request_chan()

New drivers should not use dma_request_slave_channel_reason() but
dma_request_chan(). The former is a macro to the later so this change do
not effect the driver in any way.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add DMA support

Make it possible to transfer i2c message buffers via DMA.
Start/Stop/Sending_Slave_Address and some data is still handled using
the old state machine, it is sending the bulk of the data that is done
via DMA.

The first byte of a transmission and the last two bytes of reception are
sent/received using PIO. This is needed for the HW to have access to the
first byte before DMA transmit and to be able to set the STOP condition
for DMA reception.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: fixed a checkpatch warning]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: don't open code of_device_get_match_data()

This change will also make Coverity happy by avoiding a theoretical NULL
pointer dereference; yet another reason is to use the above helper function
to tighten the code and make it more readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: disable PM in multi-master mode

In multi master mode, the IP core needs to be always active for
arbitration reasons. Get the config from DT and set up PM depending on
the config.

Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove macros dealing with flags

These macros don't really hide complexity, but C idioms. Removing them
makes the code easier to read IMO and make a planned extension easier.

Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: disable runtime PM correctly in slave mode

When we also are I2C slave, we need to disable runtime PM because the
address detection mechanism needs to be active all the time. However, we
can reenable runtime PM once the slave instance was unregistered. So,
use pm_runtime_get_sync/put to achieve this, since it has proper
refcounting. pm_runtime_allow/forbid is like a global knob controllable
from userspace which is unsuitable here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: rcar: honor additional i2c timings from DT

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: switch to i2c generic dt parsing

Switch to the new generic functions. Plain convert, no functionality
added yet.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor probe function a little

The probe function is a little bit messy, something here, something
there. Rework it so that there is some order: first init the private
structure, then the adapter, then do HW init. This also allows us to
remove the device argument of the clock calculation function, because it
now can be deduced from the private structure. Also, shorten some lines
where possible. This is a preparation for further refactoring.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: handle difference in setting up non-first message

Signed-off-by: Ryo Kataoka <ryo.kataoka.wt@renesas.com>
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: clean up after refactoring

Update the comments to match current behaviour. Shorten some comments.
Update copyrights.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: revoke START request early

If we don't clear START generation as soon as possible, it may cause
another message to be generated, e.g. when receiving NACK in address
phase. To keep the race window as small as possible, we clear it right
at the beginning of the interrupt. We don't need any checks since we
always want to stop START and STOP generation on the next occasion after
we started it.

This patch improves the situation but sadly does not completely fix it.
It is still to be researched if we can do better given this HW design.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: check master irqs before slave irqs

Due to the HW design, master IRQs are timing critical, so give them
precedence over slave IRQ.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: don't issue stop when HW does it automatically

The manual says (55.4.8.6) that HW does automatically send STOP after
NACK was received. My measuerments confirm that.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: init new messages in irq

Setting up new messages was done in process context while handling a
message was in interrupt context. Because of the HW design, this IP core
is sensitive to timing, so the context switches were too expensive. Move
this setup to interrupt context as well.

In my test setup, this fixed the occasional 'data byte sent twice' issue
which a number of people have seen. It also fixes to send REP_START
after a read message which was wrongly send as a STOP + START sequence
before.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor setup of a msg

We want to reuse this function later.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove spinlock

After making sure to reinit the HW and clear interrupts in the timeout
case, we know that interrupts are always disabled in the sections
protected by the spinlock. Thus, we can simply remove it which is a
preparation for further refactoring. While here, rename the timeout
variable to time_left which is way more readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove unused IOERROR state

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: rework hw init

We don't need to init HW before every transfer since we know the HW
state then. HW init at probe time is enough. While here, add setting the
clock register which belongs to init HW. Also, set MDBS bit since not
setting it is prohibited according to the manual.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: make sure clocks are on when doing clock calculation

When calculating the bus speed, the clock should be on, of course. Most
bootloaders left them on, so this went unnoticed so far.

Move the ioremapping out of this clock-enabled-block and prepare for
adding hw initialization there, too.

Reported-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: Revert the latest refactoring series

This whole series caused sometimes timeouts and even OOPSes on some
r8a7791 Koelsch boards. We need to understand and fix those first.

Revert "i2c: rcar: clean up after refactoring"
Revert "i2c: rcar: revoke START request early"
Revert "i2c: rcar: check master irqs before slave irqs"
Revert "i2c: rcar: don't issue stop when HW does it automatically"
Revert "i2c: rcar: init new messages in irq"
Revert "i2c: rcar: refactor setup of a msg"
Revert "i2c: rcar: remove spinlock"
Revert "i2c: rcar: remove unused IOERROR state"
Revert "i2c: rcar: rework hw init"

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: Remove obsolete platform data support

Since commit 4baadb9e05c68962 ("ARM: shmobile: r8a7778: remove obsolete
setup code"), Renesas R-Car SoCs are only supported in generic DT-only
ARM multi-platform builds. The driver doesn't need to use platform data
anymore, hence remove platform data configuration.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[wsa: removed now unused ret value and cast to proper enum type]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add support for r8a7795 (R-Car H3)

Enable the I2C core for this SoC. I add a new type because this version
has new features (e.g. DMA) which will be added somewhen later.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: enable RuntimePM before registering to the core

The core may register clients attached to this master which may use
funtionality from the master. So, RuntimePM must be enabled before, otherwise
this will fail. While here, move drvdata, too.

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: rcar: clean up after refactoring

Update the comments to match current behaviour. Shorten some comments.
Update copyrights.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: revoke START request early

If we don't clear START generation as soon as possible, it may cause
another message to be generated. To keep the race window as small as
possible, we clear it right at the beginning of the interrupt. We don't
need checking since we always want to stop START and STOP generation on
the next occasion after we started it.

This patch improves the situation but sadly does not completely fix it.
It is still to be researched if we can do better given this HW design.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: check master irqs before slave irqs

Due to broken HW design, master IRQs are more timing critical, so give
them precedence over slave IRQ.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: don't issue stop when HW does it automatically

The manual says (55.4.8.6) that HW does automatically send STOP after
NACK was received. My measuerments confirm that.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: init new messages in irq

Setting up new messages was done in process context while handling a
message was in interrupt context. Because of the HW design, this IP core
is sensitive to timing, so the context switches were too expensive. Move
this setup to interrupt context as well.

In my test setup, this fixed the occasional 'data byte sent twice' issue
which a number of people have seen. It also fixes to send REP_START
after a read message which was wrongly send as a STOP + START sequence
before.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor setup of a msg

We want to reuse this function later.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove spinlock

We make sure to reinit the HW in the timeout case; then we know that
interrupts are always disabled in the sections protected by the
spinlock. Thus, we can simply remove it which is a preparation for
further refactoring. While here, rename the timeout variable to
time_left which is way more readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove unused IOERROR state

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: rework hw init

We don't need to init HW before every transfer since we know the HW
state then. HW init at probe time is enough. While here, add setting the
clock register which belongs to init HW. Also, set MDBS bit since not
setting it is prohibited according to the manual.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use proper type for timeout

wait_event_timeout returns long, not int.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use adapter default for timeout

5 seconds is a very large timeout, and it is hardcoded. Use the default
timeout from 'struct adapter' which is 1 second. It can also be modified
from userspace for specific workloads via i2c-dev.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: report slave capabilities to users

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: constify platform_device_id

The platform_device_id is not modified by these drivers and core uses it
as const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: slave: rework the slave API

After more discussion, brave users, and additional datasheet evaluation,
some API updates for the new I2C slave framework became imminent. The
slave events now get some easier to understand naming. Also, the event
handling has been simplified to only need a single call to the slave
callback when an action by the backend is required.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add slave support

The first I2C slave provider using the new generic interface.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove sign-compare flaw

gcc rightfully says:

drivers/i2c/busses/i2c-rcar.c:198:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: check for no IRQ in rcar_i2c_irq()

Check if the ICMSR register (masked with the ICMIER register) evaluates to 0 in
the driver's interrupt handler and return IRQ_NONE in that case, like many other
drivers do.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: make rcar_i2c_prepare_msg() *void*

rcar_i2c_prepare_msg() always returns 0, so we can make this function return
*void* and thus remove the result check in rcar_i2c_master_xfer().

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: simplify check for last message

rcar_i2c_master_xfer() needlessly compares the message pointers (using indirect
addressing) in order to detect the last I2C message, while it's enough to only
compare the message indexes.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix RCAR_IRQ_ACK_{RECV|SEND}

Bits 8-31 of all registers reflect the value of bits 0-7 on reads and should be
0 on writes, according to the manuals. RCAR_IRQ_ACK_{RECV|SEND} macros have all
1's in bits 8-31, thus going against the manuals, so fix them.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Revert "i2c: rcar: remove spinlock"

This reverts commit 150b8be3cda54412ad7b54f5392b513b25c0aaa7.

The I2C core's per-adapter locks can't protect from IRQs, so the driver still
needs a spinlock to protect the register accesses.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix MNR interrupt handling

Sometimes the MNR and MST interrupts happen simultaneously (stop automatically
follows NACK, according to the manuals) and in such case the ID_NACK flag isn't
set since the MST interrupt handling precedes MNR and all interrupts are cleared
and disabled then, so that MNR interrupt is never noticed -- this causes NACK'ed
transfers to be falsely reported as successful. Exchanging MNR and MST handlers
fixes this issue, however the MNR bit somehow gets set again even after being
explicitly cleared, so I decided to completely suppress handling of all disabled
interrupts (which is a good thing anyway)...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-rcar: Drop class based scanning to improve bootup time

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
While we are here, remove the indentation for the array setup because
such things always break after some time.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message. For example,
k.alloc and v.alloc failures use dump_stack().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: update copyright and license information

Make clear that the driver is GPL v2 only. Remove FSF address. Remove
filename in comment. Update copyright information.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: janitorial cleanup after refactoring

Remove some obvious comments, remove some superfluous debug output (the
error code carries the same information), some white space fixing...

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: reuse status bits as enable bits

Status register and enable register are identical regarding their
layout. Use the bit definitions for both.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: remove spinlock

The i2c core has per-adapter locks, so no need to protect again.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor status bit handling

The old macros made it harder to see what was actually happening.
Replace them with something more readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor setting up msg

Setting up a read or write message is similar enough to be done in one
function. Also, move a helper function into the new function since it is
only used here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: check bus free before first message

We should always check if the bus is free, independently if it is a read
or write. It should be done before the first message, though. After
that, we ourselves keep the bus busy. Remove a 'ret' assignment which
only silenced a build warning.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor irq state machine

Remove the seperate functions and use designated constants. As readable
but less overhead. Actually, this is even more readable since the old
function used a mix of "=" and "|=".

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: refactor bus state machine

Remove the seperate functions and use designated constants. As readable
but less overhead.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: no need to store irq number

We use devm, so irq number is only needed during probe.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: not everything needs to be a function

Very basic operations, just called once, can also go to the caller.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add compatibles for additional SoC

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: bail out on zero length transfers

This hardware does not support zero length transfers. Instead, the
driver does one (random) byte transfers currently with undefined results
for the slaves. We now bail out.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: i2c-rcar: deprecate class based instantiation

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add compatible entry for r8a7791

While we are here, also brush up the devicetree binding documentation.
The example was an inappropriate copy from the sh_mobile driver.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix NACK error code

The response to a bus NACK is to return -ENXIO instead of the
-EREMOTEIO being currently returned by the driver.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use devm_clk_get to ensure clock is properly ref-counted

The current i2c-rcar driver does clk_get() without a corresponding
clk_put(). Add the clk to the driver private data and then get it
with the devm functions so that it is released when the driver is
unbound.

Note, we do not call clk_prepare_enable() at this point due to the
very possible magic that is being done by the pm_runtime system
underneath the driver.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: do not print error if device nacks transfer

The i2c-rcar driver currently prints an error message if the master_xfer
callback fails. However if the bus is being probed then lots of NAKs
will be generated, causing the output of a number of errors printed.

To solve this, disable the print if the error is not -EREMOTEIO.

An example of running i2cdetect:

10: i2c-rcar e6530000.i2c: error -121 : 15
-- i2c-rcar e6530000.i2c: error -121 : 15
-- 12 i2c-rcar e6530000.i2c: error -121 : 15
-- i2c-rcar e6530000.i2c: error -121 : 15
-- i2c-rcar e6530000.i2c: error -121 : 15
-- i2c-rcar e6530000.i2c: error -121 : 15
-- i2c-rcar e6530000.i2c: error -121 : 15
-- i2c-rcar e6530000.i2c: error -121 : 15

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fixup rcar type naming

b720423a2627f045133bec39a31fe2bc0dab86f3
(i2c: rcar: add rcar-H2 support)
added R-Car H2 support on i2c-rcar.

The R-Car I2C type is based on SoC generation
(Gen1 = E1/M1/H1, Gen2 = E2/M2/H2),
but added naming was H1/H2 instead of Gen1/Gen2.
Gen1/Gen2 is better naming on this driver.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: use per-device clock

Using the same clock for all device instances is non-portable and obtaining
clock references by an ID without using a device pointer is discouraged.
This is also not needed, because on platforms, where this driver is used,
suitable clocks are available for the I2C controllers, that are children of
the peripheral clock and just pass its rate 1-to-1 to controllers. This
patch switches the driver to obtain references to correct clocks.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: fix clk_get() error handling

When clk_get() fails, it returns an error code, not a NULL. This patch
fixes such an error handling bug.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add Device Tree support

This patch adds Device Tree support to the i2c-rcar driver and respective
documentation.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: get clock rate only once and simplify calculation

There is no need to repeatedly query clock frequency, where it is not
expected to change. The complete loop can also trivially be replaced with
a simple division. A further loop below the one, being simplified, could
also be replaced, but that would get more complicated.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: (cosmetic) remove superfluous parenthesis

A recent patch added even more superfluous parenthesis to those, which
already were there. Remove them again.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: rcar: add rcar-H2 support

This patch modify I2C driver of rcar-H1 to usable on both rcar-H1 and rcar-H2.

Signed-off-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: use dev_get_platdata()

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: Convert to devm_ioremap_resource()

Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: remove __dev* attributes from subsystem

CONFIG_HOTPLUG is going away as an option. As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: Jean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: rcar: fix section mismatch

Give the driver struct a name according to the 'standard' to fix:

WARNING: vmlinux.o(.data+0x11798): Section mismatch in reference from the variable rcar_i2c_drv to the function .devinit.text:rcar_i2c_probe()
...
WARNING: vmlinux.o(.data+0x1179c): Section mismatch in reference from the variable rcar_i2c_drv to the function .devexit.text:rcar_i2c_remove()

Reported-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

i2c: rcar: used devm_request_and_ioremap() instead of devm_ioremap()

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: add Renesas R-Car I2C driver

R-Car I2C is similar with SH7760 I2C.
But the SH7760 I2C driver had many workaround operations, since H/W had bugs.
Thus, it was pointless to keep compatible between SH7760 and R-Car I2C drivers.
This patch creates new Renesas R-Car I2C driver.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>